Engines may utilize various cooling jackets in the head and block to provide cooling. However, there may be competing objectives for the cooling system relating to increasing engine efficiency and waste heat rejection, improving engine warm-up, maintaining peak temperature control, providing cabin heating, etc.
One approach to balance such objectives includes an engine method, comprising: selectively pumping coolant with a single pump to each of a first cylinder head coolant jacket and a cylinder block coolant jacket based on engine temperatures, discharging coolant from the first cylinder head coolant jacket to a heating circuit line including a vehicle interior heater, and discharging coolant from the cylinder block cooling jacket and back to the single pump. For example, an engine cooling system may include a single pump coupled to both an inlet to the first cylinder head coolant jacket and an inlet to the cylinder block coolant jacket. A first shut-off element may be positioned between the pump and the cylinder block while a second shut-off element may be positioned between the pump and the cylinder head. Adjusting positions of the first and second shut-off elements may control a flow rate and/or flow percentage of coolant through each of the first cylinder head coolant jacket and the cylinder block coolant jacket. For example, during an engine cold-start, an engine warm-up phase may be initiated. During this phase, the first shut-off element may be closed to allow coolant to flow only through the first cylinder head coolant jacket of the cylinder head. This coolant then flows to the vehicle interior heater and back to the pump. Stopping coolant flow to the cylinder block may allow the engine to heat more quickly, thereby improving engine performance and reducing fuel consumption. Further, by flowing coolant through only the cylinder head and into the vehicle interior heater, the interior of the vehicle could be heated up at the same time, thereby increasing comfort of vehicle passengers.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.